A novel hepatitis B virus surface antigen immunoassay as sensitive as hepatitis B virus nucleic acid testing in detecting early infection.

Background: The aim was to considerably enhance the sensitivity of hepatitis B virus (HBV) surface antigen (HBsAg) detection and investigate whether the window period for HBV detection could be reduced.

Study Design And Methods: A high-sensitivity chemiluminescent enzyme immunoassay (CLEIA) was developed for quantitative HBsAg detection by a combination of monoclonal antibodies, each one for a specific epitope of HBsAg, and by improving the conjugation technique. The sensitivity of the assay was compared with that of the existing chemiluminescent immunoassay (CLIA).